Boris furthers his retreat from an In-Out referendum. So why did he sign up for one in the first place?

Until recently, Boris Johnson seemed to be offering himself as the leader of the movement within the party for an In-Out referendum. This push to the head of the queue stretched through David Cameron's difficult summer, during which Nick Clegg came out against the boundary reform plan he'd previously backed, all the way to the autumn's party conference, at which the Mayor was greeted like a rock star.

That Boris didn't declare for Out passed some of these enthusiasts by. It shouldn't have done - for despite writing some of the wittiest critiques of Brussels ever penned, this son of a former Euro MP has never been an Outer. And this morning, in a speech at Reuters, he has consolidated the about-turn he made recently on his support for the People's Pledge - which he signed earlier this year, thus exciting those expectations about his support for an In-Out poll in the first place.

The Mayor's position turns out to be remarkably similar to that sketched out behind the Times paywall yesterday by Rodney Leach: yes to the single market, no to almost everything else. Boris called in his speech for Britain to "maximise the benefits of EU membership and the single market without
being kicked out". He said that a referendum should be held with the question: "Do you want to stay in the EU single market as renegotiated? Yes or No?"

All this will come as a relief to Downing Street, I'm sure. The question that remains is: why did the Mayor play so fast and loose with the Outers in the first place?

11.45am Update It's worth pointing out that Boris also said: "If people don’t think the new relationship is an
improvement, then they will exercise their sovereign right to leave the EU". This is, as I say, not the People's Pledge position, nor UKIP's, nor that of the Conservatives who want an In-Out referendum - but very much that of Lord Leach or David Davis or, say, Bill Cash.

3pm Update

It's possible to read the Mayor's speech as a further turning of the screw on David Cameron. After all, Boris's position seems now to be: renegotiate or leave. The Prime Minister's position, as Patrick O'Flynn notes above, is to stay in.

This is certainly the Evening Standard's take. It describes the Mayor as "launching a blistering attack on David Cameron"...claiming that the Prime Minister’s position on fiscal union is “completely intellectually dishonest”...making "a direct challenge to Mr Cameron" by laying out "a new vision for Britain".

However, The Telegraph reports its own columnist's speech rather cooly, describing it as "another variation of Mr Johnson's policy on an EU referendum. Last month, he called for an "in-out" vote, before saying he did not
favour such a "simple" question a few days later. Today, he has argued that the referendum should be on Britain's membership of
the single market".

And it's notable that there's no clear majority take on Twitter - see above by way of example. One of the aim of the speech will have been to clarify the Mayor's position, but a lot of people are evidently very sceptical.